Kerbal Orion Program
Kerbal Space Program (KSP) is possibly the darling of the entire Kickstarter/crowd-funding indie game scene right now - perfectly mixing mad genius with playable fun, it's a game we've had much coverage of, such as here and here, and even a preview written by none other than yours truly. But now, it seems that building these fictional rockets containing little green men have been taken as serious business by a select few.
A mod has been released recently which details an alternative consideration to rocket engines in the 1950s, where scientists apparently thought of utilizing atomic explosions beneath rockets to propel them into space, surfing the blast-wave. As awesome as that sounds, it was not implemented for some strange reason involving safety or something, and thus abandoned... until now. Yep, check out the video above. You might want to cover your ears.